I. Field
The subject specification relates generally to switched mode power supplies and, more particularly, to switched mode power supplies that dynamically adjust switching frequency based at least in part upon an operation mode for wireless communication, or a band or channel in which the mode operates.
II. Background
In wireless communication, information is typically multiplexed, modulated, digitized, and conveyed over the air-interface through carriers with frequencies with specific frequency bands. Numerous wireless communications bands are available, even though the majority of bands are regulated. Wireless bands can be associated with specific technologies for wireless communications. Each of these technologies provides a mode for wireless communication, wherein each mode exploits bandwidth, or available spectral space allocated to the technology, in specific manners. The specific aspects employed for communication by the various technologies generally are identified as a mode of operation for wireless communication, or simply a mode of operation. Illustrative examples of modes of operation include GSM (global system for mobile communications), EVDO (Evolution Data Optimized), CDMA (code division multiple access), WCDMA (wideband code division multiple access), UMTS (universal mobile telecommunication system), UMB (ultra-mobile broadband), HSPA (high speed packet access), WiMAX (Worldwide Interoperability for Microwave Access), GPS (global positioning system) GLONASS (Global'naya Navigatsionnaya Sputnikova Sistema, or Global Navigation Satellite System (English)), Bluetooth, etc.
Modes of operation have associated protocols for communication (e.g., frequency division multiplexing, time division multiplexing, code division multiplexing, amplitude modulation, frequency modulation, phase modulation, . . . ) and formalisms that support the communication protocols, as well as electronic circuitry that facilitates operation on analog and digital signals and their mutual conversion in order to convey and receive the signals according to a particular mode of operation. In wireless devices, power is provided by a battery which delivers a direct current (DC) voltage largely bound within a specific range, and the battery power is typically converted to DC voltages via an intermediary circuit or power supply in order to power the various electronic circuitry that facilitates wireless communication, as well as to support electronics such as display electronics, sound electronics, programmable logic arrays, application processor(s), memory(ies), and so on. To perform efficient power management, switched mode power supplies (SMPSs) are generally employed in wireless communications. In conventional systems, SMPSs operate at a fixed switching frequency, which is generally set when a wireless device powers on, and remains fixed throughout operation. Determination of a suitable switching frequency for a given mode of operation may be time consuming and relies upon laboratory testing; however, such expense may be justified in conventional systems that operate in substantially a single mode of operation.
As wireless technology continues to increase its presence in individuals' daily routines, market forces are heavily driving wireless technology advances with the objective to deliver improved services, e.g., data rate, content, and mobility. Moreover, as business and personal development becomes more global in nature, to ensure an expected and consistent wireless presence, wireless devices are migrating from single-mode apparatuses to multi-mode, multi-service work and entertainment mobile platforms. Accordingly, power management typically accomplished through SMPSs operating at static switching frequencies optimized for a single mode and service (e.g., voice) are becoming unable to operate efficiently and without introducing performance degradation. As an example, in view of the rich variety of wireless services provided by network operators, SMPSs have started to degrade quality of wireless service as a result of interference or lower power efficiency than desired.